Fluorine containing azo compounds



Patented Dec. 18, 1945 FLUORINE CONTAINING AZO COMPOUNDS James G.McNally and John R. Byers, Jr., Rochester, N. Y., assignors to EastmanKodak Company, Rochester, N. Y., a corporation of New Jersey No Drawing.Application October 22,1942,

Serial No. 462,958

6 Claims.

This invention relates to new azo compounds and their application forthe dyeing of organic derivatives of cellulose.

We have found that navy blue to black shades which can be dischargedwhite can be obtained on organic derivatives of cellulose by dyeing themwith a dye having the formula:

wherein Z stands for a member selected from the group consisting of ahalogen atom, an acylamino group, an alkyl group and an alkoxy group,

n stands for a member selected from the group consisting of 0, 1 and 2and R and R1 each stands for a member selected from the group consistingof an alkyl group and a hydroxyalkyl group, diazotizing the dye on thefiber and developing th diazotized dye with 2-hydroxy-3-naphthoic acid.The dyeing process just described has been found. particularly of valuein connection with the dyeing of cellulose acetate silk and especiallyso for the production of black shades on this material. Our inventionincludes both the monoazo and disazo dye compounds referred to above.

It is an object of our invention to provide new azo compounds suitablefor the dyeing of organic derivatives of cellulose, especially celluloseacetate silk. Another object is to provide dyeings on material made ofor containing an organic derivative of cellulose which are of goodfastness to light and washing. A further object is to .provide celluloseacetate silk textile materials dyed a black shade of excellent fastnessto light and washing. Other objects will hereinafter appear.

Typical organic derivatives of cellulose, which may be dyed with the2.20 compounds of our invention, include the hydrolyzed as well as theunhydrolyzed cellulose organic acid esters such as cellulose acetate,cellulose formate, cellulose propionate or cellulose butyrate and thehydrolyzed as well as the unhydrolyzed mixed oragm'c acid esters ofcellulose such as cellulose acetatepropionate, celluloseacetate-butyrate and the cellulose ethers such as methyl cellulose,ethyl cellulose or benzyl cellulose.

We have found that the azo dye compounds having the formula:

wherein X stands for chlorine, bromine or iodine and Z, R, R1 and n havethe meaning previously assigned to them when applied to celluloseacetate textile fabrics and developed with 2-hydroxy- 3-naphthoic acidyield dyeings which have the peculiar property of browning. All possibledyes of the above formula have not, of course, been prepared and testedby us but we have so tested a considerable number of such dyes and havefound that, without exception, they have the property of browning. Thatis, they turn brownish when steamed or pressed while Wet with a hotiron.

The monoazo dye compounds of our invention containing a fluorine atominstead of a chlorine, bromine or iodine atom, however, do not have theundesirable property of browning. Thus, because they do not brown, thenavy-blue to black dyeings obtained with our dye compounds may besteamed or pressed while wet with a hot iron Without detriment to thedyeing. This constitutes an important and unexpected advantage whichcould not have been predicted.

The free amino dye compounds of our invention combine good speed ofdyeing with good .exhaustion. Thus, these dye compounds dye rapidly andevenly at 80-85 C, with good exhaustion. This property makes themvaluable for box dyeing. Certain members of this series also have goodspeed of dyeing and exhaustion at temperatures of (SO- C. and thesecompounds are of value for jig dyeing operations. Further, these freeamino dye compounds have excellent solubility in water and do not tendto form gummy deposits. When diazotized on the fiber and coupled with2-hydroxy-3-naphthoic acid, desirable navy blue to black shades ofexcellent fastness to light and washing, readily dischargeable to white,are obtained. The properties enumerated which are possessed by the dyecompounds of our invention make them of unusual industrial importance.

In the initial dyeing operation the free amino dye compounds can. beapplied in concentrations, for example, from to 3% by weight of the dyeto the material undergoing dyeing. Higher concentrations can be employedif desired but are ordinarily unnecessary. Pretty orange-yellow dyeingsare obtained in this initial dyeing operation. For the developmentoperation following the diazotization of the free amino dye compound onthe fiber, an excess of 2-hydroxy- S-naphthoic acid is ordinarilyemployed. The intensity of shade obtained will vary depending upon theamount of the free amino dye absorbed by the fiber in the initial dyeingoperation. With concentrations up to about 1% by weight, navy blueshades are obtained while, with concentrations ranging from about 1%upwards by weight, black shades are obtained. From this it is seen thatthe intensity of the shade increases with an increase in the amount offree amino dye applied to the fiber. Thus, with low concentrations, navyblue shades can be obtained, while with high concentrations deep blackshades are obtained.

The following examples illustrate the invention: 1

Example. 1.Preparation of 4-amino-2-fluorobenzeneazodi-p-hydroxyethylcmiline 15.6 grams of 1-amino-2-fluoro-4-nitrobenzene are slurriedin a mixture consisting of cc. of hydrochloric acid (specific gravity1.19) and 50 cc. of water. When all of the lumps have been broken up andthe amine compound is in solution, the reaction mixture is cooled to atemperature approximating 05 C. by the addition of ice, for example,following which the amine compound is diazotized by adding quickly aconcentrated solution of '7 grams of sodium nitrite in Water. Thediazotization is carriedout while maintaining a temperature of 05 C.Upon completion of the diazotization reaction which requiresapproximately one hour, the mixture is.

filtered to remove any aminoazo compound formed during the diazotizationreaction. The volume of the filtrate is about 250 cc.

18.1 grams of di-p hydroxyethylaniline are dissolved in a mixtureconsistin of '15 cciof hydrochloric acid (specific gravity 1.19) and 150cc. of water. The resulting solution is cooled to a temperatureapproximating 0-10" C. by the addition of ice; To this solution is addedthe diazonium solution prepared above at a fairly rapidp-hydroxyethylaniline. After standing for about;

30 minutes the reaction mixture is slowly and carefully made justalkaline to litmus by the addition of sodium carbonate. By thisprocedure the dye compound is brought down in finely divide'd state andis in condition for the ensuin reduction wherein the nitro group isreduced to an amino group.

The slurry formed above is heated to 65-70 C. and a solution of grams offused'sodium sulfide in 100 cc. of hot water, filtered to i free it frommetallic sulfides, is added, all at once, with stirring. A temperatureof about (SS- C. is maintained during the addition of the sodium sulfidesolution and during the ensuin reduction which requires about one hour.The red-brown slurry resulting upon addition of the sodium sulfidesolution changes color' to a dark brown and finally to a lighterred-brown at which point the desired dye compound begins to crystallizefrom solution. reduction operation, the heating and stirring are stoppedand the reaction mixture is allowed to cool to room temperature. Thereaction mixture is then filtered, washedclean of sodium sulfide withcold water and dried at'room temperature. The foregoing example istypical of the manner of preparation ofthe free amino monoazo dyecompound of our invention and; following the procedure described in theexample, any of the free amino compounds having the formula indicatedhereinbefore can be prepared.

These free amino dye compounds are ordinarily applied to the materialundergoing coloration in the form of an aqueous suspension which can beprepared by grinding the dye to a paste in the presence of soap or othersuitable dispersing agent and,dispersing. the resulting paste in water.Dyeing operations can, in the case of cellulose acetate silk, forexample, be conducted at temperatures of 70-85" C., although, asindicated hereinbefore, in some cases somewhat lower temperatures can beused. Similarly, somewhat higher temperatures than those indicated canlikewise be employed although these higher temperatures are ordinarilyunnecessary. In accordance with the usual dyeing practice, the materialto be dyed will ordinarily be added to the dyebath at a temperaturelower than that at which the main portion of the dyeing is to beeffected. A temperature approximating 45-55 0., for example, followingwhich the temperature of the dyebath is raised to that selected forcarrying out the dyeing operation. Suitable dispersing or solubilizingagents that can be employed for preparing suspensions of the dye includesoap, sulforicinoleic acid and sulfonated oleic, stearic or palmiticacid or salts thereof such, for instance, as the sodium or ammoniumsalts.

The following example illustrates one satisfactory way in which the azodyes of our invention containing a free amino group may be applied tocellulose acetate fibers.

Example A 1.5 parts of 4-amino-2-fiuorobenzeneazodi-5-hydroxy-ethylaniline are finely ground with soap and dispersed in 3000parts of water. The dispersion thus prepared is heated to a temperatureapproximating 45 C. and 100 parts of cellulose acetate in the form offabric or yarn, for example, areadded to the dyebath after which thetemperature is raised to -80 C. and the material worked for 15 minutesat this latter temperature. Upon completion of the dyeing operation, thecellulose acetate material is removed, washed with soap and rinsed Wellwith water. It will be found to be dyed a pleasing orangeyellow shade.

Diazotz'zation and development of the dye After the material has beenrinsed after dyeing it is diazotized in a hath made up as follows:

, For each 10 grams of cloth, 1 gram of sodium After completion of thenitrite is dissolved in a mixture containing 2 grams of concentratedhydrochloric acid (35%) and 300 cc. of water. The diazotizationtreatment is given for 30-45 minutes at a temperature of about 20 C.Upon completion of the diazotization reaction, the fabric is removed andthoroughly rinsed with water following which it is ready fordevelopment.

Following the diazotization treatment the material is developed,preferably immediately, in a bath made up as follows: For every 10 gramsof cloth, 10 cc. of a 5% stock solution of 2-hydroxy- 3-naphthoic acidand 1 cc. of glacial acetic acid are added to 300 cc. of water. (Thestock solution of 2-hydroxy-3-naphthoic acid is made by dissolving 10grams of 2-hydroxy-3-naphthoic acid in cc. of 5% NaOI-I and then adding100 cc. of water.) The cellulose acetate cloth from the diazotizationtreatment is entered in the developing bath at 30 C. and the temperatureis gradually raised to 60 C. over a 30 minute period and the bath iskept at this temperature for an "239L179 additional 30 minutes.Following this treatment,

the cellulose acetate material is removed, washed well with water anddried.

By the dyeing operations just described, a deep black shade whichpossesses excellent fastness to light and washing is obtained. Aspreviously explained, by the use of lesser or greater amounts of the dyecompound containing a free amino group lighter or darker shades can'beobtained. The dyeings obtained in accordance with our invention arereadily discharged to substantially apure white by the usualreductiondischarges such as, for instance, the monozinc salt of formaldehydesulfoxylic acid (Rongalite), sodium hydrosulphite and sodiumformaldehyde sulphoxylate.

The developing bath made up as described above has a pH value of 4.0. Byincreasing the amount of acetic acid added the pH will be lowered andthe shade obtained on the fabric Will be greener. Raising the pI-I bydecreasing the amount of acid added results in a redder'shade beingobtained. It will be understood that the dyeing operations justdescribed are applicable to the other dye compounds of .our inventiondescribed hereinafter and are not limited to the particular monoazo anddisazo dyes usedin these dyeing operations. The same general results'are obtained regardless of the particular dye compound used.

The monoazo dye compounds of our invention containing a free .aminogroup and having the formula givenhereinbefore can be prepared(following the general procedure given in connection with thepreparation of 4-amino-2-fiuoro- T benzeneazodi p hydroxyethylaniline.That is, diazotized .1-amino-2-fiuoro-4-nitrobenzene is coupled with acoupling component having the formula:

wherein R, R1, Z and n have the meaning previously assigned to them andthe nitro group of the monoazo dye compound thus obtained is reduced toan amino group.

Monoazo dye compounds of our invention which can be prepared inaccordance with the procedure described hereirrbefore include:

.1. it-amino 2 fluorobenzeneazomethyl, p-hydroxyethylaniline 2. 4 amino2 fluorobenzeneazoethyl, 5 hydroxyethylaniline 3.4-amino-2-fiuorobenzeneazoethyl, [3, dihydroxypropylaniline 4.4-amino-2-fluorobenzeneazoethyl, (i dihydroxypropyl-m-toluidine 5.4-amino-2-fluorobenzeneazoethyl, 3, dihydroxypropylcresidine 6.4-amino-2-fluorobenzeneazodi p hydroxy ethyl-m-chloroaniline 7,4-amino-2-fluorobenzeneazoethyl, 3, dihydroxypropyl-m-chloroaniline 8.l-amino-2-fluorobenzeneazodi p hydroxy ethyl-m-fiuoroaniline 9. 4 amino2 fluorobenzeneazoethyl, 'y hydroxypropyl-m-=bromoaniline4-amino-2-fluorobenzeneazodi B hydroxy ethyl-m-iodoaniline 11. 4 amino 2fluorobenzeneazodimethyl m.-

chloroaniline Nation "and "finally with "water. washing the carbontetrachloride liquors are As will be-understood, the clisazo dyecompounds 'of ourinvention can beprepared by coupling the diazotizedmonoazo dye compounds of the invention with 2-hydroxy-3-naphthoic acid.Normally, the disazo dye compound is formed on the in the mannerdescribed hereinbefore. Where it is desired to obtain the dyecompoun'dper -se, the diazotized monoazo dye compound is coupled with -a slightexcess of 2-hydroxy-3- naphthoic acid over that theoretically requiredto combine with the diazotized monoazo dye compound.

In order that our invention may be clearly understood, the preparationof 1-amino-2-fiuoro-4 nitrobenzene is described hereinafter. Briefly,this compound is obtained by first preparing, 1,2- difluoro-4-nitrob'enzen'e and converting this compound to 1-amino 2fiuoro-4-nitrobenzene.

Preparation of 1,2-difluo1'o-4mitfobenzene 250 cc. of concentratedsulfuric acid (specific gravity 1.84) and 220 grams or concentratednitric acid (specific gravity 1.42) are mixed together in a suitablereceptacle, and cooled to 0 C. While holding the temperature between 0and 5 'C., 62 grams of o-difiuorobenzene are stirred in dropwise duringa period of 45 minutes. After the addition of the'o-difluorobenzene iscomplete, "the temperature of the reaction mixture drops and the mixtureis stirred for one hour at -10 C. Stirring is continued for anadditional three 'hours while the temperature is permitted to rise to l4C. following which the temperature of the reaction mixture is graduallyraised to 25 C. over a 30 minute period and stirring is continued atthis temperature for another 30 minutes. 625 grams of cold water arethen added, the temperature rising to 4050 C. The oily reaction productis separated from the reaction mixture by extraction with carbontetrachloride, two or more such separations being employed. The'combinedcarbon tetrachloride liquors are washed with watenthen with a dilutesodium bicarbonate .so-

After the final dried with calcium chloride overnight following whichthe carbon ttrachlorideis removed by distillation at atmosphericpressure at a temperature upto 100 C. The pressure is now reduced in thestill and distillation continued taking a cut up to 90 C. at 30millimeter pressure. At this point the receiver is changed and a furtherfraction distilling at -81 C. at 14 millimeters pressure is fractionatedoff. This fraction consisting almost exclusively of1,2-difiuoro-4-nitrobenzene is an oily liquid weighing190 grams or 85.6%of the theoretical amountof 222 grams. Preparation of1-amino-2-fluor0-4-nitrobenzene while shaking to room temperature andthen the reaction mixture consisting of water, ammonia and solid ispoured out of the autoclave and the liner is washed with water. Thecrude product is recovered by filtration and dissolved in methylalcohol. The methyl alcohol solution is filtered and the filtrate iscooled in an ice salt bath while water is slowly added to the alcoholicsolution to eflect precipitation of the 1-amino-2-fluoro-4-nitrobenzene. Upon filtration and drying, 26.4 grams of1-amino-2-fluoro-4-nitrobenzene are obtained, which is 90% of thetheoretical amount of 30.8 grams. The melting point is 135136 C.

The majority of the coupling components which can be employed'in thepreparation of the azo dye compounds of our invention are knowncompounds. However, as the preparation of certain of these compounds maynot be described in the art, we would note that these compounds, ingeneral, are prepared by subjecting compounds having the formula gym. f

wherein Z and n have the meaning previously assigned to them toappropriate treatment to replace the hydrogen atoms of the free aminogroup with 'alkyl, and hydroxyalkyl groups. The manner of introducingthese latter groups is so well.

known to the art that it need not be described here.

It will be understood that-while the application of our dye compoundshas been illustrated primarily in connection with the dyeing of cellu-.lose acetate they are, as has been stated, suited for the dyeing oforganic derivatives of cellulose in general. Thus, other organicderivatives of cellulose may be dyed using the method illustrated inconnection with the dyeing of cellulose acetate. I

We claim: 7 l. The azo dye compounds having the formula:

, 2. The azo dye compounds having the formula:

Q 5 I V COOH wherein R. and R; each stands for a member selected fromthe group consisting of a lower alkyl grou and a lower hydroxyalkylgroup.

3. The azo dye compound having the formula:

4. Organic derivative of cellulose textile fibers colored adischargeable shade by a dye having the formula:

-o0orr wherein Z stands for a member selected from the group consistingof a halogen atom, a lower ali- "phatic acylamino group, a lower alkylgroup and v a lower alkoxy group, n stands for a member selected fromthe group consisting of 0 and l, and R and R1 each stands for a memberselected from the group consisting of a lower alkyl group and a lowerhydroxyalkyl group.

5. A cellulose acetate dyed a dischargeable shade by a dye having theformula:

wherein Z stands for a member selected from the group consisting of ahalogen atom, a lower aliphatic acylamino group, alower alkyl group anda lower alkoxy group, 1!. stands for a member selected from the groupconsisting of 0 and 1, and R. and R1 each stands for a member selectedfrom the group consisting of a lower alkyl group and a 'lowerhydroxyalkyl group.

6. A cellulose acetate textile material colored a dischargeable shade bythe dye having the formula:

COOH

JAMES G. McNALLY. JOHN R, BYERS, JR.

